A supported iMac with OS X 10.6.1 or later. The table below shows iMac computers that support TDM, the required cables, and the port of the computer to which you are connecting the iMac.

iMac Model

Cable Supported

Port on Source Computer

iMac (27-inch Late 2009)

Mini DisplayPort to Mini DisplayPort

Mini DisplayPort or Thunderbolt

iMac (27-inch Mid 2010)

Mini DisplayPort to Mini DisplayPort

Mini DisplayPort or Thunderbolt

iMac (Mid 2011)

Thunderbolt to Thunderbolt

Thunderbolt

iMac (Mid 2012 and later)

Thunderbolt to Thunderbolt

Thunderbolt

Note that the iMac (Retina 5K, 27-inch, Late 2014) does not support Target Display Mode.

How do I enable TDM?

Make sure both computers are turned on and awake.

Connect a male-to-male Mini DisplayPort or ThunderBolt cable to each computer.

Press Command-F2 on the keyboard of the iMac being used as a display to enable TDM.

Note: In Keyboard System Preferences, if the checkbox is enabled for "Use all F1, F2, etc. keys as standard functions keys," the key combination changes to Command-Fn-F2.

How do I exit TDM?
To leave TDM, press Command-F2 on the keyboard of the iMac that is in TDM. You can also exit TDM if you shutdown or sleep either computer or detach the cable.

Can I use a third-party keyboard or older Apple keyboard to enable TDM?
Some older Apple keyboards and keyboards not made by Apple may not allow Command-F2 to toggle display modes. You should use an aluminum wired or wireless Apple keyboard to toggle TDM on and off.

Can I use TDM in Boot Camp?
Target Display Mode is not supported under Boot Camp.

About Target Display Mode configuration options:

Can I connect more than one TDM-capable iMac to my computer in TDM?
Yes, as long as each iMac you want to use in TDM is using a ThunderBolt connection and is connected directly to a ThunderBolt port on a supported computer. Keep in mind the limitation for the maximum amount of ThunderBolt displays a system can support as explained in Thunderbolt ports and displays: Frequently asked questions (FAQ). An iMac in TDM behaves like a ThunderBolt display.

Can I connect one TDM-capable iMac to another TDM iMac and then to my computer?
No, each iMac that will operate in TDM must be connected directly to a Mini DisplayPort or ThunderBolt port on the computer with which you are using it. Connecting one iMac to a main computer then another iMac to that iMac will cause the last iMac to operate in TDM for the other iMac rather than the main computer.

Can I use the built-in camera or connect USB, ThunderBolt, or FireWire devices to my iMac when in TDM and have them work on my main computer?
A supported iMac works like any other external display while it is in Target Display mode, except that you cannot access its built-in camera or USB, ThunderBolt, and FireWire ports. To use external devices while in TDM mode, connect those devices to the computer the iMac in TDM is connecting to.

Can I use the iMac in TDM as a display for my gaming console, DVD player, or other device?
The Mini DisplayPort port on a supported iMac can receive DisplayPort compliant video and audio signals. Converters not made by Apple may provide options to convert other electrical, video, and audio protocols to Mini DisplayPort or Thunderbolt compliant signals.

Functionality of the iMac while in Target Display mode:

Do applications running on the iMac I'm using as a TDM display continue to work in TDM?
Applications running on the 27-inch iMac computer remain open and running while it is in TDM.

How to I adjust brightness, volume, and perform control of media playback when the iMac is in TDM?
Use the keyboard of the iMac in TDM to adjust display brightness and sound volume and to control media playback of applications running on the iMac in TDM. Other keyboard and mouse input is disabled on the iMac while it is in TDM. When using a Thunderbolt-equipped iMac as your TDM display (running OS X 10.7 or OS X 10.8 on your source computer), you can also adjust the TDM display's brightness and volume via System Preferences > Displays.

Will my iMac in TDM sleep or shutdown on its own?
OS X on the TDM iMac ignores some sleep requests, but choosing Sleep, Restart, and Shut Down will still work. If the external source goes into idle display sleep, the TDM iMac will go dark until activity resumes on the external source.

Important: Information about products not manufactured by Apple is provided for information purposes only and does not constitute Apple’s recommendation or endorsement. Please contact the vendor for additional information.